On the skin, they are located on the basal layer of the epidermis and, occasionally, on the dermis. They project their dendrites through the Malpighii stratum where they transfer their melanosomes to keratinocytes (Figure 1). This melanocyte-keratinocyte association is called epidermal melanin unit and is formed, in humans, by one melanocyte and about thirty-six keratinocytes.8,13,14